Hi... I recently emailed our Australian Svetlana distributor asking a few fair questions. He ofcourse never returned my email so I thought I would ask you old pros. I like using Svetlana winged c 34's I have in stock two unmatched pairs. One is textered 74, another 76. Another unmatched pair is a little further out at 62, the other 68. I want to know what these numbers stand for, is it gain, output???? And furthermore will I notice any difference using them in my 50w? Thanks guys.